// part1:C15:15.35:Query_base.h
// class Query_base.
#ifndef QUERY_BASE_H__
#define QUERY_BASE_H__
#include "Query.h"
class Query_base {
  friend class Query;   
  protected:
  using line_no = TextQuery::line_no; 
  ~Query_base() = default;
  private:
    virtual QueryResult eval(const TextQuery&) const = 0;
    virtual std::string rep() const = 0;
};
#endif
